My HVAC system has been acting up for a while now and I can't find any threads that talk about the specific problem I am having. Most of the time when I start up my 2007 Solstice GXP, there will be a clicking noise (not the fuel pump clicking) (about 2 clicks per second, almost like the turn signal but slightly different) coming from right behind the gauge cluster. If it is clicking, the HVAC system will only blow out hot air no matter if AC is on or not or if temperature dial is all the way to cold (also know about the 1 click heating issue). If it is not clicking (rarely happens), then the AC will work, but usually only when temp dial is all the way to cold. In the past I have been able to do the recalibration and that would make it work for a while, however when I tried that this weekend, a loud thumping noise started from the middle of the dash and the recalibration never completed. This put the HVAC system into emergency mode. Anyone have any suggestions? I haven't tried soldering the resistor in place because it seems like there is something larger going on than just that. Any help would be appreciated.